


The Brotherhood of the Horcruxes

by homoamphibians



Series: HP AU #1 [1]
Category: Harry Potter - J. K. Rowling
Genre: Angsty Siblings, Brotherhood, Gay Regulus Black, Gen, Good Regulus Black, Horcrux Hunting, Horcruxes, Noble House of Black More Like Fucked Up House of Black, Regulus Black & Lily Evans Potter Friendship, Regulus Black Lives, Sirius Black & James Potter Friendship, Sirius Black & Lily Evans Potter Friendship, Sirius Black Lives, aromantic Sirius Black
Language: English
Status: In-Progress
Published: 2019-02-21
Updated: 2019-06-28
Packaged: 2019-11-01 14:34:19
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 5
Words: 4,618
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17869073
Author URL: https://archiveofourown.org/users/homoamphibians/pseuds/homoamphibians
Summary: "Would Master like anything else before Kreacher is dismissed?""...Siri... I need him."What if Regulus Black never died? What if he was saved? What if everything we know about the Harry Potter series was changed by an 18 year old and his brother?Find out how one man can change the fate of the world, with nothing and no one on his side besides his older and arguably less mature brother.





	1. Chapter 1

"Kreacher, I order you to switch the locket and leave with it after I take care of the liquid. You must leave as soon as possible with the locket.And then you must destroy it! It's the only way Kreacher. Listen to me." The young man, who still appeared to be a boy took a shot of the disgusting liquid as his house elf watched, helplessly. 

Instantly he was thrown onto the ground, visibly shaken. His mind rushed with thoughts, visions, memories, pain. So many emotions were flooding through him. 

He remained silent as the memories attacked him, until they stopped temporarily which he then stood up and headed to the basin again. 

"Master Regulus," the house elf said despairingly.

"Kreacher, I hate to ask this of you as I do not wish harm upon you, but will you please force the liquid down my throat so this goes faster? I do not think I will last long if I have to walk over there constantly," the man took another shot and sat down. 

"Kreacher would be honored to serve Master Regulus at any time the young Master wishes it," the house elf croaked as he walked over to the basin, head bowed and scooped up a drink of the nasty liquid. 

After Kreacher had walked over the silver eyed man, now boy again opened his mouth obligingly. The house elf poured the liquid into his mouth, shakily. 

This process repeated itself several times, Regulus whimpering on the floor by the end. 

Kreacher had switched the lockets and now stood, hunched of course, looking at his Master, his favorite Master. His voice was more croaky and choked than usual as he spoke, "Would Master like anything else before Kreacher is dismissed?" 

The usual sharpness in the grey eyes were replaced with a foggy staring. The tears had stopped but now Regulus had started mouthing words. His voice eventually solidified as he reached out his arm towards the water, "...Siri.. I need him."

Kreacher nodded and then a cracking noise was heard in the air. 

Regulus flinched at the noise and lay their helplessly. "Water..." He pushed himself towards the nearby water, ignoring the faces mindlessly staring at him. He reached out his hand and was surprised when someone grabbed onto it. "Sirius." 

No one answered. 

Regulus felt himself being pulled closer to the water. "Severus?" 

Still no answer. 

Frustrated, but still too dazed to process anything he continued his query. "Vanity? Talkalot? Mother? Father? Sirius?" 

Still no answer. His left hand had been pulled into the water. Water. Waves. Liquid. He liked the water. It was a good idea to go swim. 

"Snape? Vanity? Crouch? Mother? Father?Cissy! Siri..." His voice got more faint as he sunk further and further into the arms pulling him into the cold water. 

"Siri." A whisper escaped him before the man fell silent. He couldn't talk anymore. He couldn't breathe. Everything hurt. Maybe he needed to just relax into the arms... The arms of his friends, his family, his brother. Sirius was holding him. Everything was fine. 

 


	2. Chapter 2

Regulus was quite content to just relax into the arms holding him. The coldness was soon ignored as he found himself unable to feel. Unable to move. Unable to breathe.

Yet still even when his lungs were gasping for breath it was almost nice to take a break.  A break from the stress of his life. This was relaxing. This was perfect.

And so he let himself fade from consciousness, fade from life, and relax into the no longer cold waters.

That was until he became aware of a voice. 

"REGULUS! REG!" In between cries of the same voice, obnoxiously loud footsteps were painfully obvious to the youngest Black. The footsteps grew louder and then there was a rather intimidating yell. "NOT MY BROTHER! GET AWAY FROM MY BROTHER!" This was followed by a splooshing noise and hands letting go of Regulus.

He felt relieved, but abandoned.

And then he felt two hands grab onto him and bring him up to the surface. There was some grunting from the owner of the hands as Regulus suddenly felt very cold. And then there was the pain in his back. He was on a very sharp surface.

"Reg. Reg. You better not be dead. Regulus. Regulus. Regulus Arcturus Black!" The other man's voice became very distressed extremely.

Regulus needed to move, to say something, to tell his rescuer that he was in fact alive. But the struggle was too hard. Too much to deal with. He just wanted to go back to the dreamlike state he was in before. He wanted to be warm again. Why couldn't he be warm again? Why was everything so cold? Why was he so alone?

Sirius was staring at the lifeless body of his brother. He couldn't do anything but stare and yell at Regulus. Stare and talk to his brother who had to be alive. He didn't know what the hell he would do if Regulus was dead. "Reg. You can't be dead. I'll fucking curse you, you little bitch."

Recognition. He knew that voice. He finally recognized the voice of his rescuer. Almost automatically he retorted.Regulus' words were faint but easy to recognize, at least Sirius could interpret them easily. "Not if I curse you first."

"You little fuck, you have no idea how much I fucking worried about you, you little twat. Now I need you to read this so I can take you to get some help."

A piece of wrinkled up paper was shoved in front of Regulus' face and he groggily read the words. After reading them a few times the word sunk in. "You... you can't take me to HIS house. I'm.. I'm nothing more than a... death eater."

"Oh shut it. Do you want to live or not?" Sirius grabbed his hand and then they were apparating.

Dizzy. Everything was spinning. Regulus just wanted to lay down in bed. Maybe have a nice chat with Kreacher while sipping some tea. Where did Kreacher go anyway?

"Padfoot! Where did you go? You just disappeared!"

"I need a Healer!" Sirius avoided the question for a moment, focusing on the more important task on hand.

"Are you hu... Oh damn HE'S BROUGHT SOME INJURED PERSON BACK! LILY GET OVER HERE PLEASE DEAR!"

"I'm taking him inside." Sirius announced, dragging Regulus to his feet.

James rushed to his aid by helping to support Regulus' left side. His eyes looked at his face first and then glanced to the Dark mark, Regulus bore on his arm.

Regulus woozily looked back at the man, waiting for the inevitable protest. Waiting for the yells about how the Black was nothing more than a Death Eater. How the Potter would never allow such a filthy horrible thing in his house. How all Death Eaters, especially Regulus deserved to die. Regulus expected it. He knew it was coming. It had to be coming. He would never be allowed in a member of the Order of the Phoenix's house. Especially one that stole his brother from him. They hated each other. It was bound to happen. Why wasn't it happening?

James said nothing about putting a Death Eater on his couch, which the Black brothers were both thankful for.

This meant that the protests would come later, for now they had a lot to talk about and do. Explanations would be coming, as soon as Regulus remembered what he was even doing in that cave.


	3. Chapter 3

His eyes opened slowly. The light shining down upon his eyelids was unnerving. It was wrong. It was sharp like muggle electricity and not at all like the relaxing light magic provided. This was the first sign he was in a place he was not used to or supposed to be in.

The second sign was his memories flooding back to him. As the grogginess of sleep wore off of him, his recollection of last night resurfaced. 

Regulus Black knew he was a dead man. He was supposed to be dead. The Dark Lord had surely heard of his untimely demise and disappearance. Perhaps that was even why the Dark Lord had requested his elf specifically. 

He mentally shook his head, not wanting to alert the enemies he was surrounded by to his consciousness. The Dark Lord was not that smart. He did not know anything about Regulus, he did not know the sacrifice the youngest Black had gone through. And he never would know it. 

Instead of wasting precious time by thinking about the Dark Lord's legimancy powers, he instead listened in to the conversation around him. Becoming aware of what filth was actually in the house. 

And no. He was not referring to the hideous little mudblood Sev had obsessed over.

"Why is there a known Death Eater in your house, Prongs?" Peter Pathetic Pettigrew squeaked out. 

On the list of individuals the Slytherin hated, traitors came above mudbloods. He hated the idea of weakness, of disloyalty. And Wormtail was the embodiment of all of those things. 

Before Potter could reply, Regulus spoke first. 

"I know why I am here, but the real question is why did he see fit to bring in another Death Eater?" He inquired eloquently, gracefully sitting up at the same time. Ignoring the fluid building up in his lungs and the pain around his midsection for the moment. It was irrelevant. Regulus had felt worse pain and so had Sirius. 

Potter turned to him accusingly. "What do you mean?" 

Wormtail was stumbling over his words, "He is lying, I don't know what he is talking about." 

"Peter Pettigrew is a traitor. He joined the Death Eaters early this year, seeking protection. The Dark Lord calls him Wormtail." 

"We call him Wormtail, that proves nothing. You could have heard that from anyone!" Potter protested. 

Sirius remained silent. 

"Do you trust me?" Regulus turned to his disgrace of a brother, pleading. They needed to handle the Pettigrew situation before he waddled off to the Dark Lord and told hijm Regulus was alive. 

"Fuck no. Why would I? You're just like mother and you're a Death Eater." Sirius said coldly, moving closer to his friends. Oh right. The people he actually cared for. 

Regulus looked him right in the eyes, "You saved me from death. Let me prove myself to you. If you still don't believe me after this, then you can kill me."

"What is he going to do?" Peter clutched Sirius' arm. 

"How the hell am I supposed to know? I don't know him anymore," Siri rolled his eyes at Peter and then turned back to his actual family. "What're you gonna do, Regulus?" 

Numb to the pain his brother was trying to inflict, Regulus answered. "A simple memory charm. It won't hurt him. I'll guide Potter through how to do it. You can look tnrough someone's recent memories. This will prove the Pettigrew is a Death Eater without a doubt. He cannot hide anything with his mental speed." 

All three of the Gryffindors present glared at the snake present, who remained in his relaxed position. He was used to being constantly in war. He had been always under attack from his 10th birthday on. 

"Fine. Tell me the spell." Potter reluctantly agreed, an exasperated expression obviously placed upon his face. 

"It's Legimens and the wand movement is so," he gestured with his dominant hand, not expecting it to still have lingering pain. That was troublesome to say the least. He hadn't recalled injuring his hand, just beginning the drowning process.

There was a couple minutes of silence as James Potter cast the spell and Sirius Potter held Peter in his arms. 

"He's telling the truth," Potter broke the silence, obviously bewildered that the Slytherin was being completely and utterly honest. 

Regulus would have been offended if he didn't have urgent business that required his immediate attention. He muttered a quick 'accio', took SIrius' wand, and then quickly erased Peter's memories of this whole event. 

"What the fuck, Reg?" Sirius disarmed him.

"I would have expected you to trust me at least a little bit." Regulus picked up his brother's wand and gently tossed it to him. 

"We'll trust you a little bit once you explain." Potter said, speaking for the both of them. It really didn't matter who spoke because they were basically the same person anyway at this point. 

He cast a dirty look at the Gryffindors. "Throw the rat out and I'll tell you everything."

 

 


	4. Chapter 4

The rat had not been properly disposed of, the Gryffindors deciding the best course of action would be to send him home. To make sure there was no suspicion. 

He would have preferred to see the filth die and send that to the Death Eaters as a message. His name would be clear from that,of course he was no fool, but stopping the mole from continuing to infiltrate the Order would help change the tide of the war. 

But no.

Apparently, they could not bear to kill their friend. Their brother. 

It was interesting. 

Sirius Black did not care when his brother who was not flesh and blood betrayed him. He would keep that 'brother' alive. But when he had betrayed his brother by blood, he could not care less whether that brother died.

It was a rebellion thing.

Regulus stood for everything that Siri utterly despised, a reminder of the past that haunted them both, whether or not Siri chose to actually acknowledge the fact that his brother had also lived that same childhood did not matter, Regulus just for being who he was, became a trigger for the trauma they had both experienced. Leaving Sirius to  want him dead. 

Wormtail used to stand for everything that Siri loved. It was rather easy to see that the bias would remain in place after the betrayal. 

After all, if you had to choose between the reminder of imprisonment or the reminder of freedom, it's fairly obvious who one would pick. 

He could not blame Sirius for choosing his betrayer, but he would be lying if he said it had not stung the heart he had so tried to make imperviously numb.  

He glanced up, staring at the two wands pointed directly at his face, ready to kill him as soon as he slipped up. 

"Is this place secure?" Was the bored question that slipped off his tongue easily. 

Potter seemed a bit surprise at his grace under pressure but Sirius was used to this by now. 

"Fidelious charm protected. Safest place for a snake like you to hide in," The other Black responded, glaring at Regulus who smirked in response. 

For a life or death situation, this was rather amusing. He was almost glad to see that nothing had changed with Sirius, that his brother was still the fired up Gryffindor who hated Reg with all of his being. 

"Anyone else in the house besides the..." He paused for a moment, evaluating that saying the slur would probably get him thrown out of the house, "muggleborn girl?" 

"My son. But you won't be seeing him." Potter glared harder at him.

Ah. This explained some of the more extreme defensive behavior.

Regulus rolled his eyes in annoyance,"I was inquiring after whether or not more Order members were in the house. I could not care less what your baby is up to." 

"Are you going to talk or not? Because I have no hesitation with killing you," Sirius muttered. 

They both knew that was a lie but Regulus didn't want to challenge a headstrong boy like his brother was. 

"The Dark Lord came to me, asking a favor. He wished to borrow my elf, Kreacher. I could not refuse, of course, as this would irritate the Dark Lord. At this point I was already having doubts, I had been having doubts since I was sixteen about following him. But I never had a large enough reason to put a price on my head. Kreacher went with the Dark Lord, to this cave. Kreacher was forced to drink this potion that made him suffer beyond anyone's comprehension. It puts the consumer into a hallucinatory experience of pure pain. The Dark Lord then put this locket into the basin. This locket was no ordinary locket. It was a horcrux," Regulus was interrupted by Potter.

"A horcrux? What is that?"

Sirius turned to him, "An item of dark magic. Basically you kill someone and then it splits your soul in two. Half of the soul goes into the object, making you immortal unless the object is destroyed. My dearest mother loved the idea of it, never sought out to create one herself though." He then turned to Regulus, "Continue." 

"Kreacher barely made it out alive. He told me everything that happened and I created a replica of the locket. We then went back to the cave again. The lockets could not be swapped unless the potion was consumed yet again." 

Sirius rolled his eyes, "And you bastard decided to drink it yourself because Merlin forbid that something happened to your blasted elf." 

"It makes me a bastard, does it, by not forcing someone to suffer? Interesting. I thought that was the same kind of scenario that made you a hero," Regulus glared at him. 

"What makes you a bastard is the fact that you couldn't fucking care less about me or anyone suffering except for your fucking elf. You never spoke up or tried to stop Mother or Father from hurting me, and you were too much of a coward to join me. I wanted you to leave home with me. But you didn't care about me," Sirius spat out. 

"You are not the only one who grew up in that household Sirius. I don't know why you act like I had a choice. I never had a choice because I was the one that had to fill your role. I couldn't be the disappointment of the family, I couldn't get out. Our parents wanted one of us, and I couldn't force you to suffer for the rest of your life so I could escape. They didn't give a shit about you, but I did Siri. I did. I cared about you suffering which is why I didn't just run away from home like a coward. There's a reason the family didn't go after you, and it was me. I don't care if you call me a bastard or hate me or even kill me. But don't you dare say that I never cared about you. Don't you dare pretend to know like you know anything about me," Regulus hissed. 

They sat in silence for a moment. Or rather he sat in silence while the two Potters stood in silence. 

The tension in the air was palpable. 

Both brothers glaring daggers at each other, Potter standing there as if he had no idea what to do with himself. He probably did not. 

The silence was broken by a woman stepping into the living room. 

"You all need to be more quiet, you woke Harry up." She was balancing a baby on her hip, glancing from the two men standing up to the one on the couch, "Regulus." 

"Lily," he said, surprisingly keeping his tone far from cold. 

"What?" Potter stared between the two of them. "What exactly is happening?" 

"I'd like to know that as well," Sirius masked his hurt that had appeared for a second rather quickly. 

Regulus rolled his eyes, "We were in Slug Club together. And we were also prefects.: 

"That doesn't explain why you're on fucking first name basis," Sirius glared at Regulus even harder. 

Potter sighed, "Language Padfoot. Don't be a bad example for my kid. But yeah please explain." 

Lily shrugged, "He saved my life. Several times." 

"She promised she would never speak about it," Regulus muttered. 

"I haven't for your information," she shot back at him. "Finally officially turning good?" 

The Slytherin shrugged, "Depends if your husband and  _his_ brother kill me or not." 

"They won't," Lily assured him. 

Sirius still was glaring at him, "I'm confused Lils. Why exactly have you been talking cordially to a known Death Eater? He's always hated your kind and never hesitates to drop a slur." 

"We'll talk about this later. But first lunch. James?" 

"I'm not making food for him, " Potter muttered, slinking into the kitchen. 

Lily rolled her eyes as she followed him in.

"Why did you save her life? Multiple times? What are you using her for?" Sirius hissed at him, putting his wand away finally. 

Regulus sighed, "I saved her life for a friend. And then after that, because I wanted to. I may not think their kind should have access to magic or be in Hogwarts at all, but I don't want to see innocents die." 

The call for lunch interrupted his brother's retort.

They both headed into the kitchen, knowing that nothing had changed even if Regulus was sitting down at their table and eating their food. 

Things did not change that easily. 

**Notes for the Chapter:**

> wow it's been a while  
> sorry for that oops


	5. Chapter 5

To say that lunch was filled with awkward tension would be like saying Sev was mildly interested in Evans. A severe understatement. 

The tension in the air was palpable. Glares were attacking the Slytherin from all angles except one. 

He ignored them, of course, and instead ate his food silently. He briefly wondered if it was poisoned but figured the Gryffindors were too 'noble' to kill someone like that. They would prefer to kill them face to face. Not stealthily. Loudly and proudly. 

Everything they had to do had to be loud and in person. Their good deeds had to be constantly announced so they could be surrounded in praise. 

Which explained a decent amount of why they didn't trust him at all. They couldn't understand why someone would possible be quiet about the fact they performed some 'heroic' actions.

They couldn't fathom the idea of having to work under the table and stay secretive about anything. 

It was a wonder that they could even handle a such a spy organization as the Order was. They probably sent the Ravenclaws for the more precise operations and used the Gryffindors for the soldier type missions. 

"Where did Peter go?" Lily asked, conversationally. 

Both Sirius and Potter stiffened. 

Regulus shrugged, "We tossed the rat out of your home, before he could dirty anything with his filth." 

"Don't call him filthy," Potter muttered. 

The youngest, and unarguably the most mature, of the group raised an eyebrow, "Why not? Did you not go through his memories and find out that he was betraying you? Isn't loyalty the most important thing to you? You and your band of brothers, does it not matter if one kills you and your wife? Does someone leading the Dark Lord to you not make the dirtiest of the dirt?" 

"Peter was the mole in the Order?" Lily asked, to clarify. 

Sirius nodded, "Unfortunately, yeah." 

"It came at a total shock, I can't think of him like that yet," Potter admitted. 

Regulus stared at him in disbelief, "It came as a total shock. How? He's a rat, how did no one expect him to act like one? Merlin knows Sirius is the Potter's dog, always willing to trot after them." 

"And we all know you're a snake, slimy and only interested in what saves your own life," his brother glared at him. 

Lily spoke gently, "Sirius. Back off a bit." 

Siri turned to her, his eyes filled with hurt, "How dare you? Listen to all my family problems and then take their side? Lily!" 

"I know family sucks, but he's trying to help," she placed a hand on him. 

Potter got up and the three of them left the room, leaving Regulus with the baby. 

Harry stared at him. 

Regulus stared back, not exactly knowing what to do. 

He was the youngest in the family. Babies weren't what he had to deal with. The only baby he could really remember meeting was Andy's. But that was a long time ago. Before he had completely cut ties with her. He was twelve. That was the last time he had had to take care of a child.

Andy had begged him to floo over, well that was not entirely true, and he had. Without a question. 

She was in tears, Ted had been attacked. She was taking care of him and needed someone to help her with Nymphadora. None of her neighbors were magical and she didn't have any friends to turn to. She had tried to contact her sisters, but they had completely cut ties with her three years ago. 

Andy had sent that message originally to Sirius, but he was under lock and key. He wasn't allowed to go anywhere. He wasn't allowed to receive messages. 

Regulus had intercepted, lying to his Mother that he was going to spend a couple days at a respectable friend's house. Instead, he had flooed over to his disowned cousin's and her mudblood husband's house.

She had barely spoken a word, only telling him what to do. She hadn't expressed surprise, she didn't talk about the fact that he had been ignoring her. Instead, the Slytherins worked together to take care of her family. 

He had stayed there for two days before leaving. A single hug and a 'goodbye' that they both somehow knew was for forever, and then he had left. 

That was six years ago. He hadn't seen her since, or taken care of a child. 

There was a child in front of him now, and Regulus felt like he had to take care of this one. At least it would give him something to do. 

He offered a small smile to the child. 

Harry smiled an extremely sloppy wide smile back, 

It was interesting. This offspring was actually like a child. That was the joy of being a halfblood, he assumed. After all, no pureblood children had ever acted like children. Or at least, they hadn't continued those behaviors for long. They had learned. 

The man waved at the child. 

The child drooled in response. 

Regulus sighed and stood up, walking over to Harry. He wiped the kid's mouth with a cloth. He then picked up the baby and carried him into the living room. 

Harry gurgled. 

The pureblood stared at him. 

Were babies supposed to make such atrocious sounds? Perhaps it meant the Potter spawn was expressing joy? 

That sounds similar to something Andy had told him. 

He was probably right. Child caring for was extremely less advanced than his typical skill level. 

Regulus could hide his mind from the Dark Lord, a skill that only Cissy and Sev could do as well, he could handle being alone with an infant for a couple of minutes. Or perhaps longer from how Potter was hollering that 'Padfoot' better get back inside the house. 

"Don't be a Gryffindor like Potter, if you absolutely have to be a Gryffindor be one like your mother," he whispered in the baby's ear. 

Harry wriggled at that. 

Regulus took that as an agreement, "I'm holding you to that. If I survive this war, I'm making sure you're not your dad, or Sirius." 

Those were empty words. He was not as foolish to believe that he would live through taking down the Dark Lord. He would sacrifice himself to destroy every last horcrux. 

Even if he somehow managed to survive, the Gryffindors would never allow him to set foot in this house again. 

He would not be seeing Harry again, once he set off. 

But it was a nice sentiment. 

Perhaps in another life, one where his sacrifice was not guaranteed. 

**Notes for the Chapter:**

> me: has three essays to write and acts to study for  
> also me: update time
> 
> hope you enjoyed the bit of family interaction that Regulus remembered in this chapter. it's my headcanon that he was close to all three of his cousins. like he was closest with Narcissa, sorry that's the rule, but he cared about Andromeda and Bellatrix a lot as well.


End file.
